Interstitial cystitis (in-ter-stish-uhl sĭ-stī’tĭs) or bladder pain syndrome (IC/BPS) is a chronic condition that consists of recurring pain, pressure, or discomfort in the bladder and pelvic region, often associated with urinary frequency (needing to go often) and urgency (feeling a strong need to go). It affects approximately 4 to 12 million Americans, and it can affect anyone of any age, race, or sex.

While it is thought to be more prevalent in women than men (~3-8 million women vs. ~1-4 million men in the US), issues of misdiagnosis may have led men to be underrepresented in these numbers. While the prevalence of IC/BPS in children is unknown, there are adults with the condition who note that their symptoms started in childhood.

The cause(s) of IC/BPS remain yet to be fully explained. However, most IC/BPS experts agree that multiple factors may be involved. Some bladder-related factors include inflammation, mast cell dysfunction, and thickening or reduced elasticity of the bladder lining (also known as fibrosis). In contrast, non-bladder factors include central sensitization, which involves a “sensitized” central system. This means some people with IC/BPS have a nervous system that becomes ‘extra sensitive’ over time—it means your body may react more strongly to things that didn’t used to hurt. This isn’t in your head—it’s a known biological process that can happen after stress, trauma, or ongoing pain.